1. Field of the Invention
This invention relates to the long term care of potted plants, and in particular to a novel plant feeder compartmented so as to contain slow-release fertilizer pellets for providing nutrition to the potted plant over a long period of time, with a portion of the feeder above the pellets utilizing sponge-like material serving as a source of moisture, to assure sufficient moisture for proper activation of the slow release pellets, despite irregular watering of the plant by the caretaker.
2. Description of the Prior Art
It has long been known to utilize fertilizer-containing devices that are to be inserted into the ground adjacent the roots of a plant, tree or bush to provide nutrition over a relatively long period of time.
One example of this type of device is represented by the Kingman U.S. Pat. No. 2,145,934 entitled "Plant Irrigating and Feeding Device." Kingman's device is conically shaped for easy insertion adjacent the roots of a growing plant, and adapted to contain a mass of saturable or absorbent material capable of taking up water and preferably containing fertilizer of a soluble character. However, the Kingman patent is not suitable for use with potted plants for a variety of reasons, and by way of example, this patentee says nothing about his feeder being constructed to proportionately match the size of a typical indoor potted plant so that the feeder could hold a sufficient amount of fertilizer to provide nutrition to the plant over a prolonged period.
In addition, although Kingman utilizes in his device a mass of saturable or absorbent material charged with fertilizer of a soluble character, his sponge-like material serves an entirely different purpose than that involved in the instant invention. Kingman's sponge is designed to absorb a soluble fertilizer and then, as water migrates down through the sponge, the fertilizer is carried out to the roots of the plant. Entirely missing is the use of new technology fertilizer having a "slow release" characteristic that will provide nutrition to the plant over a period of many months.
Continuing with Kingman's device, although the nutrients will rapidly migrate out of his feeder, this presents no big problem inasmuch as his feeder is intended to be located in the ground, meaning that there is plenty of earth to absorb these nutrients, with any possible overdosing of the plant or tree not being a factor. In contrast, if the Kingman feeder were to be used in conjunction with a potted plant, substantially all of the fertilizer nutrients would likely wash out of his soluble fertilizer and into the soil contained in the pot in a short period of time. A potted plant equipped with the Kingman device would doubtless be overdosed, and decline rapidly.
The Smith U.S. Pat. No. 3,755,966 entitled "Deep Root Feeder and Tree Irrigater" involves the use of an elongate, cylindrical canister filled with fertilizer pellets, and designed to be used for providing nutrients to a large tree, as depicted in FIG. 4 of the Smith patent. Smith's housing is stated to be 18" long, with an outside diameter of 4", and designed to receive a canister having an open top and holes in the bottom. The canister is to be filled with fertilizer and gravel, with water entering the top of the device filtering down and ultimately reaching the roots of the tree. Because of its size and shape, it would be necessary for the gardener to dig an initial hole in the ground in the vicinity of the tree to receive the Smith device.
From studying the Smith patent it can be concluded from the size of the holes provided in the bottom of his device and the type of compressed fertilizer pellet/tablets used, that the fertilizer contained in the device will rapidly run into the ground and be absorbed. This is no particular problem when used outdoors, but as pointed out in connection with the Kingman device, a relatively unlimited amount of a fertilizer applied to the roots of a potted plant would likely cause the rapid demise of such a plant within a short time.
The Smith patent does not attempt to design and size a feeder device to structurally relate to a household potted plant. The subject matter that Smith presents is designed to relate to an entirely different structure, i.e., a large landscaped tree, with deep roots, planted in an urban area with most if not all of the ground surface around the tree paved. The purpose of this device is to provide a route for surface water to flow down to the root system, and dissolve a portion of the fertilizer pellets incased in his root irrigater/feeder.
Although Smith utilizes terms such as fertilizer pellets and time-release nutrients in his patent, it is to be understood that these terms as used by Smith relate to products of different structure and construction. The pellets/tablets he uses have a considerable amount of fiber residue--no coating technology. The nutrient fiber is mixed with a binder and compressed into different sizes and shapes. This technology is, comparatively speaking, rather crude, but when cycled wet/dry/wet it is true that a slow-release effect is obtained.
After extensive testing, it was found that in a constantly damp environment, as is to be found in many potted plants, the binder Smith uses breaks down very fast--overnight in a glass of water, and releases its nutrients. One reason Smith mixes gravel with his pellets is to let them dry out between rainfalls, to keep them from breaking down too soon. It is therefore obvious that the Smith teaching cannot be used in connection with a potted plant in an instance in which the design goal is to supply nutrition to the plant over a prolonged period of time.
The Chan U.S. Pat. No. 3,821,863 entitled "Controlled Fertilizer Feeder" is an intricate device involving a top compartment threadedly connected with a bottom compartment having a pointed configuration. The top compartment is provided with a closure cap as well as with annularly arranged apertures located approximately midway between the top and bottom of the compartment. Depending from the closure cap is a canister arranged to contain a plant fertilizer such as potassium nitrate and phosphate, with apertures provided at the bottom of the canister in communication with the top compartment. Iron bars are provided in the bottom compartment to provide a source of rust. After the pointed lower portion of the device has been driven into the ground in the vicinity of a tree, the ground is watered, causing water to flow into both the top compartment as well as the bottom compartment. As the water level rises in the top compartment above its apertures, the water will flow out through the passageway and orifices, carrying with it a measured amount of fertilizer from the top compartment into the bottom compartment. Obviously, this is a needlessly complex and expensive device.
Chan is referred to repeatedly as a "ground" fertilizing device. No teaching is set forth with regard to an arrangement that can be effectively used with a potted plant when the design goal is to supply nutrition to the plant over a prolonged period of time, and when taking into consideration the many structural parameters that must be dealt with concerning potted plants.
The intricate and multiple layers of Chan's structure dictates that the construction of his device be of considerable bulk. Something of this size and shape would be damaging to the root system of a potted plant. This point alone drives it to be used for outside plants that have root systems extending into the ground.
Also to be noted is the fact that Chan uses a water-soluble fertilizer and then utilizes a very intricate design to regulate water flow into the device, which in turn regulates how much of the soluble nutrients overflow and exit to the root system. To enable a water soluble fertilizer to be used in an appropriate manner, the user must set apertures and thus give the user the capability of regulating the water intake to stretch out the time required for total release, while still nourishing the plant correctly. However, without a truly effective control on the amount of water presented to the device, it becomes difficult if not impossible to set the water inflow apertures to some predetermined fertilizer release amounts or time involved that will be appropriate in each circumstance.
The Williams et al U.S. Pat. No. 4,158,269 entitled "Nutrient Dispersal Device" involves a hollow elongate cylindrical body section having a cap section, an apertured body section and a lower tip. One of the key aspects of the device involved the fact that the body section is of lesser diameter than the tip section, with the relatively large hole created by the tip section entering the soil preventing the soil blocking the dispersal apertures of the body section of lesser diameter. The Williams device utilizes liquid soluble plant nutrients upon the upper surface of which a spherically shaped flotation device is designed to rise and fall with the liquid level within the body section. The flotation device is designed to float into contact with the underside of the cap at the time of a heavy rainstorm, thus to prevent the entry of liquid at a rate exceeding the dispersal rate. This device, also, is a needlessly complex and expensive, and entirely unsuitable for use in conjunction with a potted plant.
Although the Williams device is designed to be installed in the ground, it could perhaps be sized such that it would fit into most potted plants. However, in latter circumstance it would appear that the flotation ball would not perform its intended function inasmuch as when liquid nutrients exit the feeder during rainfall, the ball would lower a little and immediately take on more water.
With open apertures up and down the side and with water-soluble fertilizer, there just is not anything that could be done in connection with the Williams device to slow down the release of nutrients. The nutrients would be dispersed in a short period of time, and that quantity would cause the quick demise of a potted plant.
The Kesler U.S. Pat. No. 5,533,300 entitled "Plant Feeder and Method for Feeding Plant Roots" involves a device having a water reservoir and a water conduit connected to the reservoir at one end. The other end of the water conduit is adapted to be positioned adjacent the roots of a plant to be fed. Because of the use of a water permeable plug with water soluble plant food therein, water can percolate through the conduit from the reservoir to the roots of the plant, so as to provide nutrition thereto. The patentee mentions approximately one-half of the plant feeder extending above ground. It is to be seen that the rapid dispersal of the fertilizer nutrients will likely take place, which in the case of a large tree, will cause no harm. However, if the Kesler feeder is used with a potted plant, the rapid dispersal of the fertilizer nutrients into the pot would cause a premature death of the plant.
It is therefore obvious that few if any of the devices of the prior art have been concerned with the utilization of a relatively inexpensive, reusable device for the effective and proper feeding of a potted plant over a relatively long period of time without endangering the plant due to overfeeding.